Benchmark: test 2 - MeasureThat.net

Script Preparation code:

var route = {
    "appConfigId": "8f7cd9d8534d0d10a86bddeeff7b12bc",
    "experienceId": "bb508d10530d0d10a86bddeeff7b12e9",
    "experienceName": "ACE App Builder",
    "pageProperties": {
        "chrome_header": "{\"privatePage\":{\"notificationsEnabled\":true,\"searchEnabled\":false,\"userPrefsEnabled\":true,\"contextualConfigurationItems\":{\"enabled\":false},\"globalTools\":{\"collapsingMenuId\":0,\"primaryItems\":[{\"label\":\"UserMenu\",\"icon\":\"user\",\"type\":\"menu\",\"primaryDisplay\":\"icon\",\"value\":{\"children\":[{\"label\":\"Logout\",\"position\":500,\"type\":\"navigation\",\"value\":{\"value\":{\"href\":\"/logout.do\"},\"type\":\"external\"}}]}}]}},\"publicPage\":{\"actionButtons\":[],\"notificationsEnabled\":false,\"searchEnabled\":false,\"userPrefsEnabled\":false,\"menuEnabled\":false}}",
        "ace_application_id": "1a418990530d0d10a86bddeeff7b1200",
        "chrome_footer": "{\"public_page\":{\"enable_footer_topbar\":false,\"footer_topbar_options\":{},\"enable_footer_bar\":false,\"footer_bar_options\":{}}}"
    },
    "urlPath": "now/ace-app-builder"
}

function shallowCopy(...objs) {
	const res = Object.create(null);
    for (const obj of objs) {
        for (const key in obj) {
    		res[key] = obj[key];
    	}
    }
	res.hasOwnProperty = (prop) => {
		return prop in res;
	}
	return res;
}

Tests:

spread
var res = { ...route, viewportElementId: 'uxf-viewport-screen', reinitialize: true }
shallow copy
var res = shallowCopy(route, { viewportElementId: 'uxf-viewport-screen', reinitialize: true })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
shallow copy

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

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I'll explain the benchmark and its options.

**Benchmark Definition**

The provided JSON represents two individual test cases for measuring JavaScript performance. The test cases are designed to compare two approaches: spreading an object (using the `...` syntax) versus shallow copying an object using a custom function (`shallowCopy`).

**Options Compared**

There are two main options being compared:

1. **Spreading**: This involves using the `...` syntax to spread an object's properties into a new object, effectively creating a deep copy of the original object.
2. **Shallow Copy**: This involves using a custom function (`shallowCopy`) to create a shallow copy of an object, which only copies the top-level properties without recursively copying nested objects.

**Pros and Cons**

**Spreading:**

Pros:

* More concise and expressive syntax
* Can be faster since it doesn't require explicit looping or recursion

Cons:

* May not work correctly for objects with circular references (since JavaScript's `...` syntax only creates a shallow copy)
* May have performance implications due to the overhead of creating a new object

**Shallow Copy:**

Pros:

* Ensures that all properties, including nested objects, are copied correctly
* Can be more predictable and maintainable for complex object hierarchies

Cons:

* Requires explicit looping or recursion to create a copy, which can be slower than spreading
* May require additional memory allocation since it creates a new object

**Other Considerations**

* The `shallowCopy` function is defined in the Benchmark Definition code snippet. This function takes two arguments: the object to copy and an options object with properties that affect the shallow copy process.
* The `reinitialize` property is used to control whether the copied object should be reinitialized after copying.

**Alternatives**

Other approaches could have been taken, such as:

* Using a library like Lodash's `cloneDeep` function to create a deep copy of an object
* Using a library like Immer or Redux-Immutable to manage state changes and create a shallow copy
* Implementing a custom recursive copy function without using the `...` syntax

However, these alternatives might not be as concise or expressive as spreading, while still providing a robust way to compare performance.

Related benchmarks:

test 2 (version: 0)

Comparing performance of: spread vs shallow copy

Created: 2 years ago by: Guest

Jump to the latest result

spread

shallow copy

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):